Yuka, Rinko, Saki, and Natsumi, close friends and classmates on the brink of summer vacation in their second year of middle school, face a poignant moment as Saki prepares to transfer to a new school. Eager to preserve their bond, the girls recall a mystical stone at an ancient shrine where, according to legend, wishes come true when four friends unite around it. To their astonishment, this folklore turns out to be more than just a story. Natsu-iro Kiseki delves into the enchanting experiences of the girls during their final shared summer. As they navigate trials that strain their friendships and witness their dreams materialize, these four friends unearth profound truths about themselves and each other, crafting a summer destined to be etched in their memories forever.